1. Field of the Invention:
The present invention relates in general to an interactive numerical controller for a machine tool such as, preferably, a grinding machine. More particularly, it relates to such an interactive numerical controller of the type that enables an operator to input in a conversational mode data necessary for use in a subsequent machining operation performed in accordance with a numerical control program.
2. Description of the Prior Art:
Generally, in numeral control machine tools such as grinding machines, various position data which are used in controlling the machine tool in accordance with a numerical control program have to be input into a numerical controller for the machine tool prior to the execution of machining operations. This preparatory data input procedure must also be done when the initial setting positions of the machine components are changed in connection with the change in kind of workpieces to be machined, the replacement of a life-expired grinding wheel with a fresh one and so forth.
In a known numerical control grinding machine, when the above-noted various position data are to be input into a numerical controller, a data table which lists code numbers corresponding to data items to be input is called out and displayed on a cathode ray tube (CRT) screen. A cursor on the CRT screen is moved to designate a code number corresponding to a data item to be input, and then, alphanumeric keys are manipulated to input new data. Numerical data to be input by the alphanumeric keys include those which are to be calculated by an operator, and are therefore troublesome to calculate. Further, a code allocation table is necessary for the operator to understand the relation between the code numbers and data items to be input.
That is, when preparatory position data are input manually by an operator to the numerical controller, some of the data are calculated by the operator. This may cause errors to be involved in such calculation, thereby resulting in elongating the time taken for program debugging. In addition, reference to the code allocation table makes the data input procedure complicated, and the setting of the cursor at a wrong portion on the CRT screen may cause the input data to be stored in a storage area other than an intended storage area.